There's some good words in the grandparent about who uses Java, that I respect a lot & holds enormous truth.
I don't know anything about COBOL. But neither do any of my programmer friends. But COBOL is also far from dead, yet it might as well be to the rest of the programming world, I feel like. It has no mutual impact, it's too far removed from the regular happenings, & I'm not sure how or where dialog would open.
So yes, like, I think the Roman example is really good. Communication are getting cut off, people are stuck. Things might be good here, but the world is regressing to a pre-Romanized status, with little overland travel, unable to harvest the breadth & intelligence of the many great citizens, that Java used to be a contributing key part of.
I don't think Java is stagnant or dead, it's not so glum. Micro-profile is being wonderful. DropWizard is a very lovely quite popular scene still. But right now, Java's presence in the AP Computer Science curriculum is doing an enormous amount of heavy lifting for Java, and once that dam breaks- and it doesn't seem like there are many fitting replacements atm, with all the nice neoclassical columns & facades to make the language feel academic/computer-science-y- it's gonna be harder days for Java, & the weakness within, the being more cut off, is going to hurt.
I only see RFPs for Java based technology going up.
So while they are doing lots of nice performance improvements, there are plenty of business not so happy that their 20 year investments don't run on .NET Core, and if a rewrite is needed (e.g. WCF vs gRPC) then why not just jump into something else.
Just see the lengthy roadmap, and the considerations that not everyone was happy with "AOT" (packing everything into an exe that unzips on execution).
https://github.com/dotnet/designs/blob/main/accepted/2020/fo...
Also check the repositories from Project Reunion, it is pretty much WIP right now.
On the contrary, even boring enterprises often don't actively use Java. Sure, lots of places do, but lots of places have either never adopted or dropped (or at least relegated to certain legacy systems) Java, especially, on the enterprise side, places that at some point became largely Microsoft shops, where even if they've since moved beyond that, they probably didn't go back to Java except maybe for any Android work.
Java’s mindshare just isn’t where the exciting things in this field are happening. It’s more the domain of overengineered “big data” platforms and clunky enterprise software. Yes, SAP employs a ton of java developers I’m sure, but many devs would rather switch careers than work on anything resembling a crufty ERP.
Thus, the ecosystem stagnates, due to the dead see effect - everyone who could push it forward into new areas has no interest being anywhere near it. And stagnation is a long, drawn out death all the same. It still has a ton of momentum, and millions of outsourcing devs who only know Java, so it will be with us for a while - but make no mistake, the decline started quite a while ago.